2 results
Prescribed k-symmetric curvature hypersurfaces in de Sitter space
- Part of
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- Journal:
- Canadian Mathematical Bulletin / Volume 64 / Issue 4 / December 2021
- Published online by Cambridge University Press:
- 26 November 2020, pp. 886-901
- Print publication:
- December 2021
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- Article
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Morse index and bifurcation of p-geodesics on semi Riemannian manifolds
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- Journal:
- ESAIM: Control, Optimisation and Calculus of Variations / Volume 13 / Issue 3 / July 2007
- Published online by Cambridge University Press:
- 26 July 2007, pp. 598-621
- Print publication:
- July 2007
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- Article
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Given a one-parameter family $\{g_\lambda\colon\lambda\in [a,b]\}$
of semi Riemannian metrics on ann-dimensional manifold M, a family of time-dependent potentials $\{ V_\lambda\colon \lambda\in [a,b]\}$ 
and a family $\{\sigma_\lambda\colon \lambda\in [a,b]\} $ 
of trajectories connecting two points of the mechanical system defined by $(g_\lambda, V_\lambda)$ 
, we show that there are trajectories bifurcating from the trivial branch $\sigma_\lambda$ 
if the generalized Morse indices $\mu(\sigma_a)$ 
and $\mu(\sigma_b)$ 
are different. If the data are analytic we obtain estimates for the number of bifurcation points on the branch and, in particular, for the number of strictly conjugate points along a trajectory using an explicit computation of the Morse index inthe case of locally symmetric spaces and a comparison principle of Morse Schöenberg type.
